Magnesium research最新文献

More and more studies are accumulating about COVID-19. Some aspects of the pathogenesis of the disease recall events occurring in Mg deficiency, such as a drop of T cells, increased plasma concentration of inflammatory cytokines, and endothelial dysfunction. We hypothesize that a low Mg status, which is rather common, might foment the transition from mild to critical clinical manifestations of the disease. Epidemiological, clinical, and fundamental research is needed to clarify the potential role of Mg deficiency in COVID-19.

Several studies suggest the importance of adequate magnesium intake in the prevention of diabetes and/or its complications. The main objective of this study is to determine the daily dietary intake of magnesium in type 1 Algerian pediatric diabetics. The study involved a pediatric population of 201 individuals aged from 3 to 17 years, including 96 type 1 diabetics and 105 controls. The daily dietary intake of magnesium was determined by the 24-hour recall. The correlation between the intake of magnesium and glycemic control has been assessed in diabetics. The odds ratio was used to study the relationship between dietary magnesium intake and diabetes through multinomial logistic regression. The results indicate that there are 84% of diabetics with low magnesium intake compared to 61% of controls (P = 0.001). A negative but no significant correlation was found between magnesium intake, glycemia, and HbA1c. The multinomial logistic regression model showed that daily dietary magnesium intakes, lower than EFSA adequate intake, are associated with an OR of 5.50 (1.92-15.74; P = 0.002) in adjusted model for age, sex, and BMI. It is necessary to correct the low dietary intake of magnesium by changing the eating habits of the pediatric populations in western Algeria and more particularly type 1 diabetics.

A correct magnesium (Mg²⁺) intake is essential for bone health. In particular, Mg²⁺ deficiency inhibits the proliferation of osteoblast-like SaOS-2 cells by increasing nitric oxide (NO) production through the upregulation of inducible NO synthase. At the moment, little is known about the expression and the role of TRPM7, a channel/enzyme involved in Mg²⁺ uptake, and MagT1, a Mg²⁺ selective transporter, in SaOS-2 cells. Here, we demonstrate that TRPM7 is not modulated by different extracellular concentrations of Mg²⁺ and its silencing exacerbates growth inhibition exerted by low Mg²⁺ through the activation of inducible NO synthase and consequent accumulation of NO. Moreover, MagT1 is upregulated in SaOS-2 cultured in high Mg²⁺ and its silencing inhibits the growth of SaOS-2 cultured in media containing physiological or high Mg²⁺, without any modulation of NO production. We propose that TRPM7 and MagT1 are both involved in regulating SaOS-2 proliferation through different mechanisms.

The role of magnesium in cell metabolism is complex and still not completely clarified. Although magnesium has been shown to modulate many phenomena in cells, its intracellular distribution and subcellular compartmentalization have not yet elucidated in detail, mainly as a consequence of the inadequacy of analytical techniques. The method usually employed to quantify total magnesium in cells or tissue are F-AAS or more sensitive techniques as graphite furnace AAS and inductively coupled plasma mass spectroscopy (MS). Thanks to the development of new specific fluorescent dyes, several progresses have been made in the comprehension of the fundamental biological process at the cellular and sub-cellular level. Moreover, the biological function of a chemical element in cells does not only require the determination of its intracellular quantity but also the spatial distribution of its concentration. Most of Mg²⁺-sensitive fluorescent dyes detect only the free metal ions, precluding the possibility of identifying the total pool of Mg. This review aims at giving an overview on different techniques focusing on two approaches to quantify total Mg in a small cell population or in single cells: i) Indirect Mg detection, label-based methods that represent the best choice to quantify the elemental concentration on a large cell population; ii) direct Mg detection (label-free), Synchrotron-based x-ray microscopy techniques that offer the possibility of achieving a detailed map of the intracellular concentration of a specific chemical element on single cell.

Transient Receptor Potential Melastatin (TRPM)7 is important in maintaining the intracellular homeostasis of magnesium (Mg), which is instrumental for vital cellular functions. Since the upregulation of TRPM7 has been proposed as a marker of endothelial dysfunction, we evaluated the effects of high glucose, which markedly impacts endothelial performance, on TRPM7 and intracellular Mg homeostasis in human macrovascular endothelial cells. We show that glucose-induced free radicals increase the amounts of TRPM7 as well as total intracellular magnesium. On the contrary, the highly selective Mg transporter MagT1 is not modulated by high glucose, hydrogen peroxide and low extracellular magnesium. We conclude that in endothelial cells high glucose alters Mg homeostasis through the upregulation of TRPM7.

Magnesium (Mg²⁺) is critical for a number of biological processes and 25% body Mg²⁺ is located in the skeletal muscle. Mg²⁺ transport and homeostasis systems (MgTHs) regulate intracellular Mg²⁺ concentration and muscle MgTHs are thus related to whole body Mg²⁺ homeostasis. Nonetheless, few studies have investigated the regulation of muscle MgTHs under (patho)physiological conditions. Herein, we assessed the relationship between the expression of MgTHs genes (Trpm6, Trpm7, Magt1, Mrs2, Cnnm1-4, Slc41a1-3) and relevant pathways in human sarcopenia, which is one of the most dramatic physiologic changes affecting the human body. Transcriptomic data were compared between young adult (YO, 22 y, n = 11) and old (EL, 73 y, n = 13) men from the PROOF cohort. MgTH mRNA levels did not change with aging, with the exception of a slight decrease for Slc41a3. Nevertheless, interindividual variations of mRNA levels revealed strong correlations between MgTHs in the YO group, while few were maintained in the EL muscle. Moreover, in the YO muscle, different clusters of MgTH mRNAs strongly correlated with divers physiological (BMI, blood pressure) and muscle characteristics (intramyocellular droplets, capillarization); however, most correlations changed or disappeared in the EL muscle. Further investigations of the whole transcriptome identified several sets of mRNAs correlated with defined MgTHs. There again was a sharp difference between YO and EL muscles, as the number of mRNAs correlated with MgTHs strongly decreased with aging. Gene ontology analyses of these sets of correlated mRNAs revealed 6 biological processes common to YO and EL, 3 specific to the YO (RNA processing, translation, respiration), and 2 (regulation of catabolic process, Wnt signaling) to the EL muscle. Overall, these observations lead to questions about potential resilience to muscle Mg²⁺ homeostasis in the elderly.

Background: Low magnesium (Mg) levels are linked to many diseases. Studies suggest that organic salts of Mg are more readily bioavailable than its oxide or inorganic salts used for supplements production. Unfortunately, the plethora of variables in the previous study designs complicates the making of any clear and reliable conclusions.

Methods: 14 healthy males were supplemented for five days with 400 mg Mg to saturate Mg pools before intake of the test products. Bioavailability of 400 mg Mg from Mg citrate (MgC) and Mg oxide (MgO) after single-dose administration was assessed by measuring renal Mg excretion in 24-h urine and blood plasma [Mg] at time points 0, 2, 4, 8, and 24 h.

Results: Single-dose MgC supplementation led to a significant (P < 0.05) increase in 24 h urinary Mg excretion, but this was not significant following MgO. Plasma [Mg] was also significantly higher for MgC than for MgO at 4 h (P < 0.05) and 8 h (P < 0.05). Compared with baseline levels, MgC supplementation showed a significant increase in plasma [Mg] at all time points, in contrast to MgO.

Conclusions: MgC shows higher bioavailability compared with MgO. Furthermore, urinary Mg excretion should be determined as the primary endpoint of Mg bioavailability studies.